Life Sciences Commons^™

How The Devil Ray Got Its Horns: The Evolution And Development Of Cephalic Lobes In Myliobatid Stingrays (Batoidea: Myliobatidae), Jd Swenson, J Klomp, Robert A. Fisher, Kd Crow

VIMS Articles

Manta rays and their relatives of the family Myliobatidae have pectoral fins that have been modified for underwater flight, as well as a pair of fleshy projections at the anterior of the body called cephalic lobes, which are specialized for feeding. As a unique trait with a dedicated function, cephalic lobes offer an excellent opportunity to elucidate the processes by which diverse body plans and features evolve. To shed light on the morphological development and genetic underpinnings of cephalic lobes, we examined paired fin development in cownose rays, which represent the sister taxon to manta rays in the genus Mobula. …

Long-Term Nutrient Reductions Lead To The Unprecedented Recovery Of A Temperate Coastal Region, Js Lefcheck, R J. Orth, Wc Dennison, D. J. Wilcox, Rr Murphy, K. Moore, Et Al.

VIMS Articles

Humans strongly impact the dynamics of coastal systems, yet surprisingly few studies mechanistically link management of anthropogenic stressors and successful restoration of nearshore habitats over large spatial and temporal scales. Such examples are sorely needed to ensure the success of ecosystem restoration efforts worldwide. Here, we unite 30 consecutive years of watershed modeling, biogeochemical data, and comprehensive aerial surveys of Chesapeake Bay, United States to quantify the cascading effects of anthropogenic impacts on submersed aquatic vegetation (SAV), an ecologically and economically valuable habitat. We employ structural equation models to link land use change to higher nutrient loads, which in turn …

Phylogenetic Analysis Of Apicomplexan Parasites Infecting Commercially Valuable Species From The North-East Atlantic Reveals High Levels Of Diversity And Insights Into The Evolution Of The Group, R. Xavier, R. Severino, M. Pérez-Losada, C. Gestal, R. Freitas, D. James Harris, Ana Verissimo, D. Rosado, J. Cable

VIMS Articles

Background: The Apicomplexa from aquatic environments are understudied relative to their terrestrial counterparts, and the seminal work assessing the phylogenetic relations of fish-infecting lineages is mostly based on freshwater hosts. The taxonomic uncertainty of some apicomplexan groups, such as the coccidia, is high and many genera were recently shown to be paraphyletic, questioning the value of strict morphological and ecological traits for parasite classification. Here, we surveyed the genetic diversity of the Apicomplexa in several commercially valuable vertebrates from the NorthEast Atlantic, including farmed fish. Results: Most of the sequences retrieved were closely related to common fish coccidia of Eimeria, …

Depth- And Range-Dependent Variation In The Performance Of Aquatic Telemetry Systems: Understanding And Predicting The Susceptibility Of Acoustic Tag-Receiver Pairs To Close Proximity Detection Interference, S R. Scherrer, B P. Rideout, G. Giorli, E M. Nosal, Kevin C. Weng

VIMS Articles

BACKGROUND:

Passive acoustic telemetry using coded transmitter tags and stationary receivers is a popular method for tracking movements of aquatic animals. Understanding the performance of these systems is important in array design and in analysis. Close proximity detection interference (CPDI) is a condition where receivers fail to reliably detect tag transmissions. CPDI generally occurs when the tag and receiver are near one another in acoustically reverberant settings. Here we confirm transmission multipaths reflected off the environment arriving at a receiver with sufficient delay relative to the direct signal cause CPDI. We propose a ray-propagation based model to estimate the arrival …

Characterizing The Preferences And Values Of Us Recreational Atlantic Bluefin Tuna Anglers, William Morris Goldsmith, Andrew M. Scheld, John Graves

VIMS Articles

The Atlantic Bluefin Tuna Thunnus thynnus is the target of a recreational fishery along the U.S. East Coast that is thought to be of considerable economic value. In some years, recreational landings have exceeded the sector’s annual subquota due to changes in fish availability, limited predictability of angler effort, and difficulties in realtime monitoring of catch. Understanding the drivers of angler behavior is critical for predicting how effort and harvest may vary as a function of changing fish availability, regulations, or costs. To investigate angler decision making, preferences, and values, we surveyed private recreational anglers from Maine to North Carolina …

Accuracy And Precision Of Tidal Wetland Soil Carbon Mapping In The Conterminous United States, Jr Holmquist, L Windham-Myers, N Bliss, S Crooks, Jt Morris, W. G. Reay, Et Al.

VIMS Articles

Tidal wetlands produce long-term soil organic carbon (C) stocks. Thus for carbon accounting purposes, we need accurate and precise information on the magnitude and spatial distribution of those stocks. We assembled and analyzed an unprecedented soil core dataset, and tested three strategies for mapping carbon stocks: applying the average value from the synthesis to mapped tidal wetlands, applying models fit using empirical data and applied using soil, vegetation and salinity maps, and relying on independently generated soil carbon maps. Soil carbon stocks were far lower on average and varied less spatially and with depth than stocks calculated from available soils …

Antibiotic Effects On Microbial Communities Responsible For Denitrification And N2o Production In Grassland Soils, M Semedo, Bk Song, T Sparrer, Rl Phillips

VIMS Articles

Antibiotics in soils may affect the structure and function of microbial communities. In this study, we investigated the acute effects of tetracycline on soil microbial community composition and production of nitrous oxide (N2O) and dinitrogen (N-2) as the end-products of denitrification. Grassland soils were pre-incubated with and without tetracycline for 1-week prior to measurements of N2O and N-2 production in soil slurries along with the analysis of prokaryotic and fungal communities by quantitative polymerase chain reaction (qPCR) and next-generation sequencing. Abundance and taxonomic composition of bacteria carrying two genotypes of N2O reductase genes (nosZ-I and nosZ-II) were evaluated through qPCR …

New Constraints On Coseismic Slip During Southern Cascadia Subduction Zone Earthquakes Over The Past 4600 Years Implied By Tsunami Deposits And Marine Turbidites, Gr Priest, Rc Witter, Yinglong J. Zhang, C Goldfinger, Kl Wang, Jc Allen

VIMS Articles

This correction stands to correct Figure 7c listing a low minimum slip of 12 m for Case 2 instead of the correct value of 8 m, as stated in the body of the text and depicted on the chart of cumulative slip. The corrected chart explanation and caption are shown below. This error did not affect any of the findings of the paper or the chart itself. This is a correction to the original article.

Spatial Distribution And Morphological Responses To Predation In The Salt Marsh Periwinkle, Aj Rietl, Mg Sorrentino, Bj Roberts

VIMS Articles

The salt marsh periwinkle (Littoraria irrorata) is a common and often abundant mollusk in marshes of the Gulf and Atlantic coasts of the United States. Several studies have focused on the effects of periwinkles on Spartina alterniflora production and the effects of oil on periwinkle survivability, yet the general ecology of the snail has been underreported. In this study, we measured spatial distributions, biomass, shell repair frequency, and a suite of morphological characteristics of L. irrorata at three sites in each of five regions spanning the southeastern Louisiana Coast between the Atchafalaya and Mississippi rivers. Sampling was conducted along 50 …

Time Trends Of Polybrominated Diphenyl Ethers (Pbdes) In Antarctic Biota, E Markham, Ek Brault, M Khairy, Ar Robuck, Me Goebel, Mg Cantwell, Rm Dickhut, R Lohmann

VIMS Articles

Polybrominated diphenyl ethers (PBDEs) are "emerged" contaminants that were produced and used as flame retardants in numerous consumer and industrial applications for decades until banned. They remain ubiquitously present in the environment today. Here, a unique set of >200 biotic samples from the Antarctic was analyzed for PBDEs, including phytoplankton, krill, fish, and fur seal milk, spanning several sampling seasons over 14 years. PBDE-47 and -99 were the dominant congeners determined in all samples, constituting > 60% of total PBDEs. A temporal trend was observed for Sigma 7PBDE concentrations in fur seal milk, where concentrations significantly increased (R-2 = 0.57, p < 0.05) over time (2000-2014). Results for krill and phytoplankton also suggested increasing PBDE concentrations over time. Trends of PBDEs in fur seal milk of individual seals sampled 1 or more years apart showed no clear temporal trends. Overall, there was no indication of PBDEs decreasing in Antarctic biota yet, whereas numerous studies have reported decreasing trends in the northern hemisphere. Similar PBDE concentrations in perinatal versus nonperinatal milk implied the importance of local PBDE sources for bioaccumulation. These results indicate the need for continued assessment of contaminant trends, such as PBDEs, and their replacements, in Antarctica.

Effects-Based Spatial Assessment Of Contaminated Estuarine Sediments From Bear Creek, Baltimore Harbor, Md, Usa, Se Hartzell, Michael A. Unger, Bl Mcgee, Lt Yonkos

VIMS Articles

The original publication of this paper contains an error. The correct image of figure 5 is shown in this paper.

Cohesive And Mixed Sediment In The Regional Ocean Modeling System (Roms V3.6) Implemented In The Coupled Ocean-Atmosphere-Wave-Sediment Transport Modeling System (Coawst R1234), Cr Sherwood, Al Aretxabaleta, Courtney K. Harris, Jp Rinehimer, R Verney, B Ferre

VIMS Articles

We describe and demonstrate algorithms for treating cohesive and mixed sediment that have been added to the Regional Ocean Modeling System (ROMS version 3.6), as implemented in the Coupled Ocean-Atmosphere-Wave- Sediment Transport Modeling System (COAWST Subversion repository revision 1234). These include the following: floc dynamics (aggregation and disaggregation in the water column); changes in floc characteristics in the seabed; erosion and deposition of cohesive and mixed (combination of cohesive and non-cohesive) sediment; and biodiffusive mixing of bed sediment. These routines supplement existing noncohesive sediment modules, thereby increasing our ability to model fine-grained and mixed-sediment environments. Additionally, we describe changes to …

The Competing Impacts Of Climate Change And Nutrient Reductions On Dissolved Oxygen In Chesapeake Bay, Id Irby, Marjorie A.M. Friedrichs, F Da, Ke Hinson

VIMS Articles

The Chesapeake Bay region is projected to experience changes in temperature, sea level, and precipitation as a result of climate change. This research uses an estuarine-watershed hydrodynamic-biogeochemical modeling system along with projected mid-21st-century changes in temperature, freshwater flow, and sea level rise to explore the impact climate change may have on future Chesapeake Bay dissolved-oxygen (DO) concentrations and the potential success of nutrient reductions in attaining mandated estuarine water quality improvements. Results indicate that warming bay waters will decrease oxygen solubility year-round, while also increasing oxygen utilization via respiration and remineralization, primarily impacting bottom oxygen in the spring. Rising sea …

Estimating Fishing And Natural Mortality Rates, And Catchability Coefficient, From A Series Of Observations On Mean Length And Fishing Effort, Ay Then, Jm Hoenig, Qc Huynh

VIMS Articles

Gedamke and Hoenig (2006) (Transactions of the American Fisheries Society, 135: 476-487) developed a non-equilibrium version of the Beverton and Holt estimator of total mortality rate, Z, based on mean length and thereby increased the usefulness of length-based methods. In this study, we extend their model by replacing period-specific Z parameters with the year-specific parameterization Z(y) = qf(y) + M where q is the catchability coefficient, f(y) is the fishing effort in year y, F (= qf) is the fishing mortality rate, and M is the natural mortality rate. Thus, the problem reduces to estimating just three parameters: q, M …

Assimilating Bio-Optical Glider Data During A Phytoplankton Bloom In The Southern Ross Sea, De Kaufman, Marjorie A.M. Friedrichs, Jcp Hemmings, Walker O. Smith Jr.

VIMS Articles

The Ross Sea is a region characterized by high primary productivity in comparison to other Antarctic coastal regions, and its productivity is marked by considerable variability both spatially (1-50 km) and temporally (days to weeks). This variability presents a challenge for inferring phytoplankton dynamics from observations that are limited in time or space, which is often the case due to logistical limitations of sampling. To better understand the spatio-temporal variability in Ross Sea phytoplankton dynamics and to determine how restricted sampling may skew dynamical interpretations, high-resolution bio-optical glider measurements were assimilated into a one-dimensional biogeochemical model adapted for the Ross …

Saltmarsh Plants, But Not Fertilizer, Facilitate Invertebrate Recolonization After An Oil Spill, David S. Johnson, Jw Fleeger, Mr Riggio, Ia Mendelssohn, Qx Lin, Dr Deis, A Hou

VIMS Articles

Foundation species contribute to the recovery of animal communities from disturbance by engineering, by improving habitat quality, and by regulating food availability. In a salt marsh impacted by the Deepwater Horizon oil spill, we tested the hypothesis that nutrient subsidies would enhance the positive effects of the foundation species Spartina alterniflora on the initial recolonization of benthic invertebrate communities (e.g., copepods, annelids, nematodes) by augmenting food (i.e., microalgae) availability. After two months, plantings of S.alterniflora significantly elevated the densities of the polychaete Capitella capitata, meiofauna-sized annelids, and total macroinfauna over unplanted plots. After 7months, the significant effect of plantings persisted …

Early-Holocene Greening Of The Afro-Asian Dust Belt Changed Sources Of Mineral Dust In West Asia, A Sharifi, Ln Murphy, A Pourmand, Ac Clement, Elizabeth A. Canuel

VIMS Articles

Production, transport and deposition of mineral dust have significant impacts on different components of the Earth systems through time and space. In modern times, dust plumes are associated with their source region(s) using satellite and land -based measurements and trajectory analysis of air masses through time. Reconstruction of past changes in the sources of mineral dust as related to changes in climate, however, must rely on the knowledge of the geochemical and mineralogical composition of modern and paleodust, and that of their potential source origins. In this contribution, we present a 13,000-yr record of variations in radiogenic Sr-Nd-Hf isotopes and …